Power dipper trip



Feb. 16, 1932. A, W, ANDERSON 1,845,779

POWER DIPPER TRIP Filed Sept. 19, 1930 FIG. 2. 1Q-9 Bl/Mm! ATTORN Patented Feb. 16, 1932 UNITED STATES ALVIN' W. ANDERSON, 0F FREEYORT, ILLINOIS rownn Duran Tan' Application med September 19, 1830. Serial ll'o. 483,075.

The present invention relates to power shovels and more particularly to improved means for tripping the bottoms or doors of dippers or buckets of power shovels.

The primary object of the invention is to u provide apower operated dipper trip' for power shovels.

A further object is to rovide a fluid pressure operated device of t is character ada tm ed to be controlled thru the operation o a valve disposed in a readily accessible location to the operator of the shovel.

A further object of the invention is to provide a simple trip releasing device susceptible of mounting upon the boom of existin types of power shovels for exerting a pu l upon the trip cable or line to release the dipper bottom.

A further object resides in the novel manner of controlling the fluid pressure operated trip lever to permit slack in the trip cable, and also the improved means for limiting movement of the trip lever when a pull is exerted u on the cable.

2,5 Other ob]ects and advantages of this invention will be apparent from the following detailed description, taken in connection with the accompanying drawings and in which drawings:

a0 Figure 1 is a side view of a conventional type of power shovel boom and showing the invention applied thereto.

Figure 2 is an enlarged side plan View part in section and part in elevation of the device as applied to the boom.

Figure 3 is a top plan view of Figure 2.

Referring to the drawings in detail and wherein similar reference characters designate corresponding parts thruout the several views, the improved dipper trip device nism is of typical construction and embodies the boom 5 pivotally mounted at its lower endu on the turntable 6 which also supports e driving or power means, not shown, enclosed by the usual cab 7 from which the operator controls movement of the dipper 8. The dipper 8 is supported upon the dip r stick or shipper shaft 9 which operates t ru the boom 5 for retracting and extending the dipper, and the usual hoisting cable 10 is provided for raising and lowering the dipper. Pivotall mounted at the lower end of the dipper is e usual swinging door or bottom 11 held in a closed position b a latch, not shown, having connection with lever 12l pivotally carried by the dipper stick 9.

Connected with the free end of the latch lever 12 is one end of a latch line or tiller a latch w rope 13 which extends about a sheave 14 65 carried by a swinging lever 15 pivoted upon the boom 5 and is wound upon a drum or spool 16 rotated by movement of the dipper stick 9. In operation of the device thus far described, when the dipper stick is either extended or retracted, the spool 16 is rotated for either winding or unwinding the tiller rope 13-in accordance with the movement of the dipper stick and taking up slack in the tiller ro e.`

In `this 'manually operated type of trip mechanism, a ull line is connected to the free end of the swinging lever 15 and extends to a location in the cab 7 within reach of the operator so that when a pull is exerted upon the pull line the dipper bottom will be tripped. The present invention relates to an improved fluid pressure operated means for exerting a pull upon the pull line.

p Referring now to the power operated means forming the Subj ect matter of the resent invention, the same embodies a flui cylinder 20 attached by suitable brackets 21 to the upper or outer end of a mounting plate 22 secured longitudinally upon one side of the boom 5 rearwardly of the swinging lever 15. Th-e mounting plate 22 may be secured to 'the boom as by bolts or rivets 23 as shown.

Operating within the cylinder 2O is a piston 24 to which is pivotally connected one end of a piston rod 25 that projects rearwardly beyond the open rear end of the cylinder. The rear end of the piston rod 25 is pivotally connected as at 26j to the intermediate portion of a trip lever 27 pivotally mounted at its lower end as at 28 upon the mounting plate 22. This trip lever 27 projects well above the cylinder 2O and has attached to its upper end a suitable clevis or the like 29 to which is connected a pull line or tripcable 30. The opposite end of the cable 30 is attached in any suitable manner to thev swinging lever 15 so that when the trip lever 27 is swung toward thel cab 7, the lever 15 lwill be swung about its pivot and exerta pull upon the latch Vline 13. u y

Projecting vupwardly from the forward closed or pressurey endV of the Ycylinder2() is Van apertured extension 31 for connecting one end of acontractile coil spring 32 having its opposite end suitably connected tothe trip lever 27 above the pivot 26. Thus it will be seen thatthe return spring 32 acts to normally draw the trip lever toward the cylinder 20 and move the piston 24 into the cylinder. Y

Opening into the cylinder 2O adjacent its closed end wall 20 is aninlet port coupling 34 to which is connected a preferably flexible liuid pressure line35 that extends to a control valve 36 arranged at any preferred location in the cab 7. The valve 36 may be an automatic return valve operated by foot pressure sothat when released, iiowv to the cylinder 2O is automaticallyshut 01T. The pressure for operation of thel tripping device mayeither be steam orcompressed air in accordance with the particular type of power shovel to which the device'is applied.

Connected at the pressure end of the cylinder 20 and in the example illustrated, in the end wall 20 is a pressure relief valve 38 lfor exhausting the cylinder after the tripping operation. This valve 3S may be in the form of a small drain cock and is adj usted so as to permit escape of the steam or air from the cylinder in suicient time for the next tripping operation. The reliefvalve after once being kproperly adjusted is left in its adjusted open posit-ion to permit inward movement of the piston 24 by the spring 32. The opening thru the-,valve 38 is o' course considerably smaller than the opening thru/'the inlet coupling 34so thatV a pres` sure is formed in the cylinder for operating the piston when the control valve 36 is opened. Secured to the lower `end of the mounting plate 22 is an upstanding arm`40 having its upper end offset so as to be disposed directly rearward of and in the path of movement of the trip lever 27. The upper end of this arm 40 is apertured as at 41 for receiving a threaded stem 42 on which are threaded bolts 43 adapted to be turned into binding engagement with the arm at opposite ends of the opening 41. These bolts 43 serve to permit longitudinal adjustment of the stem 42 which carries at its forward end a stop block or disc 44 to be engaged by the trip lever 27 This adjustable stop block 44 serves to limit movement of the trip lever by the piston 24 and may be adjusted topermit the proper limit of pull upon the trip cable 30.

' VTir-operation of the device for tripping the dipper bottom-11,thegoperator merely opens the control valve 36 by a pressure of the foot or `hand as the case may be and allows steam or air to enter the cylinder 20. This pressure in vthe cylinder voperates the trip lever 27 against tensionof the spring 32 and exerts a pull on the trip cable 30 which'in turthru the swinging lever 15 and latchlinej13 'releases the latch holding the dipper bottom 11. As soon as the bottoml'l is trippedthe operator releases the control valve 36,'shutting off liuid pressure to the cylinder 20 and allowing pressure in the cylinder to escape thru the relief valve 38 and the trip lever to be returned by the springv 32.l Y i Thus it will be seen that Ya simple Jand elticiently operating device of this character has been disclosed whereby the bottoms of power shovel clippers may be tripped by means of fluid pressure and with little or no manual .effort upon the part of the operator. It will also be observed that the device isA readily adaptable for use upon power shovels of con'- ventional construction. u f Y Changes in detailmay b 'e made to the form of invention herein A shown landy described, without departingfrom thespirit of 1the invention or the scopel ofthe following claims.

I claim: f y Y Vl. In fluid pressure operated trip means for dipper bottoms; a mounting plate,l a cylinder mounted upon the outer end of the plate,apiston movable inthe cylinder, a trip cable lever pivoted upon the plate rearwardly of the cylinder and projecting above the cylinder, a rod connecting the piston and lever for rearward swinging of the lever by the piston, a pressure inlet port opening into the forward end of the cylinder, means` for controlling entrance of fluid -thru'the port, a bleederV valve for the forward pressure, end of the cylinder, an adjustable stop mounted uponthe plate rearwardly of thetrip lever for limiting rearward swinging movement of the lever, an apertured extension at the forward end of the cylinder, and a'contractile coil spring connected between the extension andftrip lever for returning ythelever toward the cylinder.i

2. In a power'dippe'r trip of the class described, a. mounting plate, a c linder mounted upon the plate and provi ed at its pressure end with an exhausting aperture al piston movable in the cylinder, a trip cable lever pivoted u on the plate, a pressure inlet fitting for the cy nder, spring means normally urging the lever toward the cylinder, an arm mounted upon the plate, and a sto block adjustably carried by the arm in t e ath of swinging movement of the trip lever or controlling the limit of travel of the tri lever.

ALVIN W. ANDER ON. 

